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Zhang R, He J, Wang M, Duan S, Zhang J. Nitrate and nitrite utilization during denitrifying phosphorus removal: Electron acceptor preference and feasible process combinations. BIORESOURCE TECHNOLOGY 2024; 406:131081. [PMID: 38977037 DOI: 10.1016/j.biortech.2024.131081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 06/30/2024] [Accepted: 07/04/2024] [Indexed: 07/10/2024]
Abstract
Denitrifying phosphorus removal (DPR), which is dominated by denitrifying polyphosphate-accumulating organisms (DPAOs), is a promising process for nitrogen and phosphorus removal. Denitrifying glycogen-accumulating organisms (DGAOs) and DPAOs typically coexist in the DPR sludge, complicating the study of DPAOs' denitrification capacity. In this study, two reactors were fed with nitrate and nitrite during the anoxic phase to cultivate nitrate-DPR and nitrite-DPR sludge. Both reactors yielded high and low DGAO abundance sludges, enabling the evaluation of the denitrification capacity of DPAOs. For the nitrate-DPR sludge, the nitrite reduction rate was 1.63 times higher than the nitrate reduction rate when DPAOs were the primary denitrifiers. For the nitrite-DPR sludge, the reduction rate of nitrite was more than three times that of nitrate, irrespective of DGAO abundance. These findings indicated that DPAOs preferred nitrite to nitrate and were well suited to reduce nitrite rather than reduce nitrate to supply nitrite.
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Affiliation(s)
- Ruimiao Zhang
- School of Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, PR China; State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, PR China.
| | - Junguo He
- School of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China
| | - Mengfei Wang
- School of Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, PR China; State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, PR China
| | - Shengye Duan
- School of Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, PR China; State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, PR China
| | - Jie Zhang
- School of Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, PR China; State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, PR China
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2
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Wang X, Zhang G, Ding A, Xie E, Tan Q, Xing Y, Wu H, Tian Q, Zhang Y, Zheng L. Distinctive species interaction patterns under high nitrite stress shape inefficient denitrifying phosphorus removal performance. BIORESOURCE TECHNOLOGY 2024; 394:130269. [PMID: 38154736 DOI: 10.1016/j.biortech.2023.130269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/21/2023] [Accepted: 12/25/2023] [Indexed: 12/30/2023]
Abstract
Denitrifying phosphorus removal using nitrite as an electron acceptor is an innovative, resource-efficient approach for nitrogen and phosphorus removal. However, the inhibitory effects of nitrite on anoxic phosphorus uptake and process stability are unclear. This study investigated the total phosphorus removal performance under nitrite stress and analyzed microbiome responses in 186 sludge samples. The results indicated that the total phosphorus removal rates and dominant taxon abundance were highly similar under nitrite stress. High nitrite stress induced a community-state shift, leading to unstable dynamics and decreased total phosphorus removal. This shift resulted from increased species cooperation. Notably, the shared genera OLB8 and Zoogloea under non-inhibitory nitrite stress, suggesting their vital roles in mitigating nitrite stress by enhancing carbon and energy metabolism. The response patterns of these bacterial communities to high nitrite stress can guide the design and optimization of high-nitrogen wastewater reactors.
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Affiliation(s)
- Xue Wang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Guoyu Zhang
- Department of Environmental Engineering, School of Marine Science and Technology, Harbin Institute of Technology, Weihai 264209, China
| | - Aizhong Ding
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - En Xie
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
| | - Qiuyang Tan
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Yuzi Xing
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Haoming Wu
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Qi Tian
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Yaoxin Zhang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Lei Zheng
- College of Water Sciences, Beijing Normal University, Beijing 100875, China.
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3
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Wu T, Ding J, Yang SS, Zhong L, Liu BF, Xie GJ, Yang F, Pang JW, Ren NQ. A novel cross-flow honeycomb bionic carrier promotes simultaneous nitrification, denitrification and phosphorus removal in IFAS system: Performance, mechanism and keystone species. WATER RESEARCH 2022; 225:119132. [PMID: 36155005 DOI: 10.1016/j.watres.2022.119132] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/13/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Simultaneously achieving efficient nitrogen (N) and phosphorus (P) removal without adding external carbon source is vital for carbon-neutral wastewater treatment. In this study, a novel cross-flow honeycomb bionic microbial carrier (CF) was developed to improve the efficiency of simultaneous nitrification, denitrification, and P removal (SNDPR) in an integrated fixed-film activated sludge (IFAS) system. A parallel laboratory-scale sequencing batch reactor with the commercialized microbial carriers (CM) (CM-IFAS) was performed as the comparative system for over 233 d The results demonstrated that CF-IFAS exhibited a more consistent N removal efficiency and better performance than CM-IFAS. In the CF-IFAS, the highest N and P removal efficiencies were 95.40% and 100%, respectively. Typical cycle analysis revealed that nitrate was primarily removed by the denitrifying glycogen-accumulating organisms in the CF-IFAS and by denitrifying phosphate-accumulating organisms in the CM-IFAS. The neutral community model showed that the microbial community assembly in both the reactors was driven by deterministic selection rather than stochastic factors. Compared to those in CM-IFAS, the microorganisms in CF-IFAS were more closely related to each other and had more keystone species: norank_f_norank_o_norank_c_OM190, SM1A02, Defluviicoccus, norank_f_ Saprospiraceae, and norank_f_Rhodocyclaceae. The absolute contents of the genes associated with N removal (bacterial amoA, archaeal amoA, NarG, NapA, NirS, and NirK) were higher in CF-IFAS than in CM-IFAS; the N cycle activity was also stronger in the CF-IFAS. Overall, the microecological environment differed between both systems. This study provides novel insights into the potential of bionic carriers to improve SNDPR performance by shaping microbial communities, thereby providing scientific guidance for practical engineering.
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Affiliation(s)
- Tong Wu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR. China
| | - Jie Ding
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR. China
| | - Shan-Shan Yang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR. China.
| | - Le Zhong
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR. China
| | - Bing-Feng Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR. China
| | - Guo-Jun Xie
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR. China
| | - Fan Yang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150008, PR. China
| | - Ji-Wei Pang
- China Energy Conservation and Environmental Protection Group, Beijing 100089, PR. China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR. China
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4
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Hu T, Peng Y, Yuan C, Zhang Q. Enhanced nutrient removal and facilitating granulation via intermittent aeration in simultaneous partial nitrification endogenous denitrification and phosphorus removal (SPNEDpr) process. CHEMOSPHERE 2021; 285:131443. [PMID: 34329129 DOI: 10.1016/j.chemosphere.2021.131443] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 06/23/2021] [Accepted: 07/03/2021] [Indexed: 06/13/2023]
Abstract
A novel simultaneous partial nitrification, endogenous denitrification and phosphorus removal (SPNEDpr) system was operated for 213 days in a sequencing batch reactor to treat real domestic sewage. The nutrient removal was achieved under an operation mode of intermittent aeration at unequal intervals with low oxygen concentrations. Through optimizing intermittent aeration conditions, the removal efficiencies of total inorganic nitrogen (TIN), PO43-P and chemical oxygen demand (COD) reached 78.40%, 98.13% and 84%, respectively. Low-oxygen (0.1-0.7 mg/L) and intermittent aeration effectively inhibited nitrite oxidation bacteria (NOB), maintaining stable partial nitrification with nitrite accumulation ratio of 96.45%. Notably, intermittent aeration promoted the formation of aerobic granular sludge, with the sludge particle size increasing from 217.2 ± 5.3 to 351.8 ± 4.8 μm, thereby enhancing the TIN loss efficiency (81.3%). The predominant genus was Candidatus_Competibacter (11.6%), which stored COD as intracellular carbon source and performed the endogenous denitrification. The SPNEDpr process provided a highly efficient and economical method for treating urban sewage.
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Affiliation(s)
- Tiantian Hu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China.
| | - Chuansheng Yuan
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Qiong Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
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Rey-Martínez N, Merdan G, Guisasola A, Baeza JA. Nitrite and nitrate inhibition thresholds for a glutamate-fed bio-P sludge. CHEMOSPHERE 2021; 283:131173. [PMID: 34182653 DOI: 10.1016/j.chemosphere.2021.131173] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 04/30/2021] [Accepted: 06/06/2021] [Indexed: 06/13/2023]
Abstract
Enhanced biological phosphorus removal (EBPR) is an efficient and sustainable technology to remove phosphorus from wastewater. A widely known cause of EBPR deterioration in wastewater treatment plants (WWTPs) is the presence of nitrate/nitrite or oxygen in the anaerobic reactor. Moreover, most existing studies on the effect of either permanent aerobic conditions or inhibition of EBPR by nitrate or free nitrous acid (FNA) have been conducted with a "Candidatus Accumulibacter" or Tetrasphaera-enriched sludge, which are the two major reported groups of polyphosphate accumulating organisms (PAO) with key roles in full-scale EBPR WWTPs. This work reports the denitrification capabilities of a bio-P microbial community developed using glutamate as the sole source of carbon and nitrogen. This bio-P sludge exhibited a high denitrifying PAO (DPAO) activity, in fact, 56% of the phosphorus was uptaken under anoxic conditions. Furthermore, this mixed culture was able to use nitrite and nitrate as electron acceptor for P-uptake, being 1.8 μg HNO2-N·L-1 the maximum FNA concentration at which P-uptake can occur. Net P-removal was observed under permanent aerobic conditions. However, this microbial culture was more sensitive to FNA and permanent aerobic conditions compared to "Ca. Accumulibacter"-enriched sludge.
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Affiliation(s)
- Natalia Rey-Martínez
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona, Spain.
| | - Gökçe Merdan
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona, Spain; Department of Environmental Engineering, Namık Kemal University, Turkey.
| | - Albert Guisasola
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona, Spain.
| | - Juan Antonio Baeza
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona, Spain.
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He C, Zhuo M, Hou J. Efficient purification of toluene gas by anoxic denitrification. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:11683-11688. [PMID: 33415636 DOI: 10.1007/s11356-020-12311-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
As a part of volatile organic compounds (VOCs), toluene does harm to human health. This paper reported the purification of toluene waste gas by liquid-phase absorption and anoxic denitrification. In this work, two same biofilm reactors were set to treat toluene waste gas, one of which was added into nitrate as an electron acceptor. Then, the purification properties of toluene waste gas treated by anoxic denitrification and biological methods were compared. The results indicate that with the increase of toluene mass concentration, the toluene removal rate of the denitrifying reactor decreased slightly. When the inlet concentration increased from 50 mg m-3 to 3440 mg m-3, the removal efficiency of the denitrifying reactor remained over 94.1% while the removal efficiency of the traditional bioreactor decreased to 82.9%. The highest removal capacity of the denitrifying reactor was 127.2 g m-3 h-1, which was 11.8% higher than that of the traditional bioreactor. Toluene was degraded by denitrification inside the biofilm microenvironment hypoxia; the denitrification rate increased along with the increase of inlet concentration within certain limits and reached a maximum of 2.4 mg NO3--N L-1 h-1. Nitrate can act as an electron acceptor, and denitrification can promote aerobic degradation and intensify the concentration gradient inside the biofilm to strengthen the toluene transfer process.
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Affiliation(s)
- Chengda He
- School of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225000, People's Republic of China.
| | - Meng Zhuo
- School of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225000, People's Republic of China
| | - Jianhua Hou
- School of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225000, People's Republic of China.
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7
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Yuan C, Wang B, Peng Y, Li X, Zhang Q, Hu T. Enhanced nutrient removal of simultaneous partial nitrification, denitrification and phosphorus removal (SPNDPR) in a single-stage anaerobic/micro-aerobic sequencing batch reactor for treating real sewage with low carbon/nitrogen. CHEMOSPHERE 2020; 257:127097. [PMID: 32470541 DOI: 10.1016/j.chemosphere.2020.127097] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 04/26/2020] [Accepted: 05/15/2020] [Indexed: 05/25/2023]
Abstract
The feasibility of simultaneous partial nitrification, denitrification and phosphorus removal (SPNDPR) process was investigated in a single-stage anaerobic/micro-aerobic sequencing batch reactor for treating real sewage. Partial nitrification was maintained with average nitrite accumulation ratio of 90.3% during 266 days' operation. Removal efficiencies for NH4+-N (96.3%), total inorganic nitrogen (81.4%), and phosphorus (91.0%) were stably obtained when treated real sewage with low carbon/nitrogen (3.4), with simultaneous partial nitrification and denitrification efficiency of 73.1%. The mechanism analysis revealed that denitrifying glycogen-accumulating organisms (DGAOs) and denitrifying polyphosphate-accumulating organisms (DPAOs) played the main roles in N-removal and P-removal, respectively. Nitrite pathway and optimized use of the organic carbon available in the sewage were keys for the successful performance. Further microbial community illustrating that DGAOs Candidatus_Competibacter, DPAOs Dechloromonas, and ammonia-oxidizing bacteria Nitrosomonadaceae were main functional groups. Notably, sludge granulation was formed under long-term synchronous low dissolved oxygen and low sludge loading conditions, avoiding sludge bulking.
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Affiliation(s)
- Chuansheng Yuan
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Bo Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China.
| | - Xiyao Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Qiong Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Tiantian Hu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
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Ji J, Peng Y, Wang B, Li X, Zhang Q. A novel SNPR process for advanced nitrogen and phosphorus removal from mainstream wastewater based on anammox, endogenous partial-denitrification and denitrifying dephosphatation. WATER RESEARCH 2020; 170:115363. [PMID: 31816567 DOI: 10.1016/j.watres.2019.115363] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/27/2019] [Accepted: 12/01/2019] [Indexed: 06/10/2023]
Abstract
For achieving energy-efficient wastewater treatment, a novel simultaneous nitrogen and phosphorus removal (SNPR) process, which integrated anammox, endogenous partial-denitrification and denitrifying dephosphatation in a sequencing batch reactor with granular sludge was developed to treat mainstream wastewater. After 200 days of operation, a simultaneous high-level nitrogen and phosphorus removal of 93.9% and 94.2%, respectively was achieved with an average influent C/N ratio of 2.9. Anammox pathway contributed 82.9% of the overall nitrogen removal because of the stable nitrite production from nitrate via endogenous partial-denitrification. In addition, phosphorus was mainly removed via denitrifying dephosphatation utilizing nitrate as the electron acceptor, resulting in a significant saving of carbon sources and oxygen demands. Further, adsorption/precipitation of phosphorus occurred in this novel SNPR process, which displaced the energy source to the metabolism of glycogen accumulating organisms (GAOs) for nitrite production and alleviated competition between phosphorus accumulating organisms (PAOs) and anammox for electron acceptor. Using 16S rRNA gene amplicon sequencing analysis, the study found that anammox bacteria (8.4%), GAOs (1.5%) and PAOs (1.1%) co-existed in this system, potentially resulting in simultaneous endogenous partial-denitrification, anammox and denitrifying dephosphatation. The above results demonstrated that the novel SNPR process is a promising technique for energy-efficient wastewater treatment.
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Affiliation(s)
- Jiantao Ji
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China.
| | - Bo Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Xiyao Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Qiong Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
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Zhao J, Wang X, Li X, Jia S, Wang Q, Peng Y. Improvement of partial nitrification endogenous denitrification and phosphorus removal system: Balancing competition between phosphorus and glycogen accumulating organisms to enhance nitrogen removal without initiating phosphorus removal deterioration. BIORESOURCE TECHNOLOGY 2019; 281:382-391. [PMID: 30831518 DOI: 10.1016/j.biortech.2019.02.109] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 02/21/2019] [Accepted: 02/23/2019] [Indexed: 06/09/2023]
Abstract
The novel partial nitrification endogenous denitrification and phosphorus removal (PNEDPR) process can achieve deep-level nutrient removal from low carbon/nitrogen municipal wastewater without extra carbons. However, its performance is limited by long hydraulic retention time (HRT) and low specific endogenous denitrification rate (rNO2). This study aimed at investigating the effects of two improving strategies on PNEDPR. One was decreasing both anaerobic and anoxic reaction time for shortening HRT from 55 h to 17.5 h. The other was temporarily discharging orthophosphate-rich supernatant for balancing the competition between phosphorus and glycogen accumulating organisms to further raise rNO2 without deterioration of phosphorus removal. Results revealed that, desirable nutrient removal was obtained, as average effluent concentrations of total nitrogen and orthophosphate were 8.4 and 0.5 mg/L with their average removal efficiencies of 86.8% and 90.9%. High-throughput sequencing analysis revealed that, Candidatus_Competibacter conducted nitrogen removal endogenous denitrification and Candidatus_Accumulibacter and Tetrasphaera ensured phosphorus removal.
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Affiliation(s)
- Ji Zhao
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Xiaoxia Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Xiyao Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Shuyuan Jia
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Qi Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China.
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Population Structure and Morphotype Analysis of " Candidatus Accumulibacter" Using Fluorescence In Situ Hybridization-Staining-Flow Cytometry. Appl Environ Microbiol 2019; 85:AEM.02943-18. [PMID: 30824450 DOI: 10.1128/aem.02943-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 02/20/2019] [Indexed: 11/20/2022] Open
Abstract
"Candidatus Accumulibacter" is the dominant polyphosphate-accumulating organism (PAO) in denitrifying phosphorus removal (DPR) systems. In order to investigate the community structure and clade morphotypes of "Candidatus Accumulibacter" in DPR systems through flow cytometry (FCM), denitrifying phosphorus removal of almost 100% using nitrite and nitrate as the electron acceptor was achieved in sequencing batch reactors (SBRs). An optimal method of flow cytometry combined with fluorescence in situ hybridization and SYBR green I staining (FISH-staining-flow cytometry) was developed to quantify PAOs in DPR systems. By setting the width value of FCM, bacterial cells in a sludge sample were divided into three groups in different morphotypes, namely, coccus, coccobacillus, and bacillus. Average percentages that the three different PAO populations accounted for among total bacteria from SBR1 (SBR2) were 42% (45%), 14% (13%), and 4% (2%). FCM showed that the ratios of PAOs to total bacteria in the two reactors were 61% and 59%, and the quantitative PCR (qPCR) results indicated that IIC was the dominant "Candidatus Accumulibacter" clade in both denitrifying phosphorus removal systems, reaching 50% of the total "Candidatus Accumulibacter" bacteria. The subdominant clade in the reactor with nitrite as the electron acceptor was IID, accounting for 31% of the total "Candidatus Accumulibacter" bacteria. The FCM and qPCR results suggested that clades IIC and IID were both coccus, clade IIF was coccobacillus, and clade IA was bacillus. FISH analysis also indicated that PAOs were major cocci in the systems. An equivalence test of FCM-based quantification confirmed the accuracy of FISH-staining-flow cytometry, which can meet the quantitative requirements for PAOs in complex activated sludge samples.IMPORTANCE As one group of the most important functional phosphorus removal organisms, "Candidatus Accumulibacter," affiliated with the Rhodocyclus group of the Betaproteobacteria, is a widely recognized and studied PAO in the field of biological wastewater treatment. The morphotypes and population structure of clade-level "Candidatus Accumulibacter" were studied through novel FISH-staining-flow cytometry, which involved denitrifying phosphorus removal (DPR) achieving carbon and energy savings and simultaneous removal of N and P, thus inferring the different denitrifying phosphorus removal abilities of these clades. Additionally, based on this method, in situ quantification for specific polyphosphate-accumulating organisms (PAOs) enables a more efficient process and more accurate result. The establishment of FISH-staining-flow cytometry makes cell sorting of clade-level noncultivated organisms available.
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11
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Yun G, Lee H, Hong Y, Kim S, Daigger GT, Yun Z. The difference of morphological characteristics and population structure in PAO and DPAOgranular sludges. J Environ Sci (China) 2019; 76:388-402. [PMID: 30528031 DOI: 10.1016/j.jes.2018.06.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 06/05/2018] [Accepted: 06/05/2018] [Indexed: 06/09/2023]
Abstract
We examined how long-term operation of anaerobic-oxic and anaerobic-anoxic sequencing batch reactors (SBRs) affects the enhanced biological phosphorus removal (EBPR) performance and sludge characteristics. The microbial characteristics of phosphorus accumulating organism (PAO) and denitrifying PAO (DPAO) sludge were also analyzed through a quantitative analysis of microbial community structure. Compared with the initial stage of operation characterized by unstable EBPR, both PAO and DPAO SBR produced a stable EBPR performance after about 100-day operation. From day 200 days (DPAO SBR) and 250 days (PAO SBR) onward, sludge granulation was observed, and the average granule size of DPAO SBR was approximately 5 times larger than that of PAO SBR. The DPAO granular sludge contained mainly rod-type microbes, whereas the PAO granular sludge contained coccus-type microbes. Fluorescence in situ hybridization analysis revealed that a high ratio of Accumulibacter clade I was found only in DPAO SBR, revealing the important role of this organism in the denitrifying EBPR system. A pyrosequencing analysis showed that Accumulibacter phosphatis was present in PAO sludge at a high proportion of 6%, whereas it rarely observed in DPAO sludge. Dechloromonas was observed in both PAO sludge (3.3%) and DPAO sludge (3.2%), confirming that this organism can use both O2 and NO3- as electron acceptors. Further, Thauera spp. was identified to have a new possibility as denitrifier capable of phosphorous uptake under anoxic condition.
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Affiliation(s)
- Geumhee Yun
- Department of Environmental Engineering, Korea University, Sejong, 339-700, South Korea.
| | - Hansaem Lee
- Hyundai Engineering & Construction Co., Ltd., 17-6 Mabuk-Ro 240, Giheung-Gu, Yongin-Si, Gyuonggi-Do, South Korea
| | - Yongsuk Hong
- Department of Environmental Engineering, Korea University, Sejong, 339-700, South Korea
| | - Sungpyo Kim
- Department of Environmental Engineering, Korea University, Sejong, 339-700, South Korea
| | - Glen T Daigger
- Department of Civil and Environmental Engineering, University of Michigan, 177 EWRE Building, 1351 Beal Avenue, Ann Arbor, MI 48109-2125, USA
| | - Zuwhan Yun
- Department of Environmental Engineering, Korea University, Sejong, 339-700, South Korea.
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12
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Lanham AB, Oehmen A, Carvalho G, Saunders AM, Nielsen PH, Reis MAM. Denitrification activity of polyphosphate accumulating organisms (PAOs) in full-scale wastewater treatment plants. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2018; 78:2449-2458. [PMID: 30767910 DOI: 10.2166/wst.2018.517] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A comprehensive assessment of full-scale enhanced biological phosphorus removal (EBPR) plants (five plants, 19 independent tests) was undertaken to determine their effectiveness in terms of aerobic and anoxic P removal. By comparing parallel P uptake tests under only aerobic or under anoxic-aerobic conditions, results revealed that introducing an anoxic stage led to an overall P removal of on average 90% of the P removed under only aerobic conditions. This was achieved with negligible higher PHA and glycogen requirements, 30% lower overall oxygen consumption and with the simultaneous removal of nitrate, reducing up to an estimate of 70% of carbon requirements for simultaneous N and P removal. Varying fractions of denitrifying polyphosphate accumulating organisms (DPAOs), from an average of 25% to 84%, were found in different plants. No correlation was found between the DPAO fractions and EBPR configuration, season, or the concentration of any of the microbial groups measured via quantitative fluorescence in situ hybridisation. These included Type I and Type II Ca. Accumulibacter and glycogen accumulating organisms, suggesting that chemical batch tests are the best methodology for quantifying the potential of anoxic P removal in full-scale wastewater treatment plants.
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Affiliation(s)
- Ana B Lanham
- Department of Chemical Engineering, Water Innovation and Research Centre, University of Bath, Claverton Down, BA2 7AY, Bath, UK E-mail:
| | - Adrian Oehmen
- Chemistry Department FCT-UNL, UCIBIO, REQUIMTE, 2829-516 Caparica, Portugal; School of Chemical Engineering, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Gilda Carvalho
- Chemistry Department FCT-UNL, UCIBIO, REQUIMTE, 2829-516 Caparica, Portugal; Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Aaron M Saunders
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Per H Nielsen
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Maria A M Reis
- Chemistry Department FCT-UNL, UCIBIO, REQUIMTE, 2829-516 Caparica, Portugal
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13
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Zhang C, Qian Y, Yuan L, He S, Wang Y, Wang L. Nutrients removal performance of a denitrifying phosphorus removal process in alternate anaerobic/anoxic-aerobic double membrane bioreactors (A 2N-DMBR). WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2018; 78:1741-1752. [PMID: 30500798 DOI: 10.2166/wst.2018.456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
An alternate anaerobic/anoxic-aerobic double membrane bioreactors process (A2N-DMBR) was proposed to improve denitrifying phosphorus removal efficiency. The system was operated for 70 d under different nitrogen/phosphorus (N/P) ratios with synthetic wastewater to present the performance evaluation of nutrients removal and microbial community structure in the A2N-DMBR process. The results showed that when the influent total phosphorus (TP) was 6.4 mg/L, the corresponding N/P ratio of 8.8, the high removal capacity of nitrogen and phosphorus could be achieved with the average effluent TP and total nitrogen (TN) concentration of 0.8 mg/L and 12.0 mg/L, respectively. Periodical test showed that pH and oxidation-reduction potential (ORP) could be used as control parameters for anaerobic phosphate release, and ORP was also closely related with the phosphate uptake in anoxic phase. The high-throughput sequencing analysis revealed that the Proteobacteria and Xanthomonadales-nobank related to biological nitrogen and phosphorus removal was domination bacteria at phylum and genus level in A2N-DMBR system, with the proportion of 42.5% and 39.1%, respectively. Furthermore, Dechloromonas, which was further detected as putative denitrifying phosphorus accumulating organisms (DPAOs), was enriched (9.9%) in the system.
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Affiliation(s)
- Chuanyi Zhang
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China E-mail: ;
| | - Yunkun Qian
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China E-mail: ;
| | - Limei Yuan
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China E-mail: ;
| | - Shilong He
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China E-mail: ;
| | - Ying Wang
- School of Environment, Beiing Normal University, Beijing, 100875, China
| | - Liping Wang
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China E-mail: ;
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14
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Vieira A, Ribera-Guardia A, Marques R, Barreto Crespo MT, Oehmen A, Carvalho G. The link between the microbial ecology, gene expression, and biokinetics of denitrifying polyphosphate-accumulating systems under different electron acceptor combinations. Appl Microbiol Biotechnol 2018; 102:6725-6737. [DOI: 10.1007/s00253-018-9077-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 02/06/2018] [Accepted: 05/07/2018] [Indexed: 02/07/2023]
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15
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Effect of Free Nitrous Acid on Nitrous Oxide Production and Denitrifying Phosphorus Removal by Polyphosphorus-Accumulating Organisms in Wastewater Treatment. BIOMED RESEARCH INTERNATIONAL 2018; 2018:9192607. [PMID: 29854809 PMCID: PMC5944283 DOI: 10.1155/2018/9192607] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 03/18/2018] [Indexed: 11/17/2022]
Abstract
The inhibition of free nitrous acid (FNA) on denitrifying phosphorus removal has been widely reported for enhanced biological phosphorus removal; however, few studies focus on the nitrous oxide (N2O) production involved in this process. In this study, the effects of FNA on N2O production and anoxic phosphorus metabolism were investigated using phosphorus-accumulating organisms (PAOs) culture highly enriched (91 ± 4%) in Candidatus Accumulibacter phosphatis. Results show that the FNA concentration notably inhibited anoxic phosphorus metabolism and phosphorus uptake. Poly-β-hydroxyalkanoate (PHA) degradation was completely inhibited when the FNA concentration was approximately 0.0923 mgHNO2-N/L. Higher initial FNA concentrations (0.00035 to 0.0103 mgHNO2-N/L) led to more PHA consumption/TN (0.444 to 0.916 mmol-C/(mmol-N·gVSS)). Moreover, it was found that FNA, rather than nitrite and pH, was likely the true inhibitor of N2O production. The highest proportion of N2O to TN was 78.42% at 0.0031 mgHNO2-N/L (equivalent to 42.44 mgNO2-N/L at pH 7.5), due to the simultaneous effects of FNA on the subsequent conversion of NO2 into N2O and then into N2. The traditional nitrite knee point can only indicate the exhaustion of nitrite, instead of the complete removal of TN.
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16
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Keene NA, Reusser SR, Scarborough MJ, Grooms AL, Seib M, Santo Domingo J, Noguera DR. Pilot plant demonstration of stable and efficient high rate biological nutrient removal with low dissolved oxygen conditions. WATER RESEARCH 2017; 121:72-85. [PMID: 28521237 PMCID: PMC7388030 DOI: 10.1016/j.watres.2017.05.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 05/11/2017] [Accepted: 05/12/2017] [Indexed: 05/04/2023]
Abstract
Aeration in biological nutrient removal (BNR) processes accounts for nearly half of the total electricity costs at many wastewater treatment plants. Even though conventional BNR processes are usually operated to have aerated zones with high dissolved oxygen (DO) concentrations, recent research has shown that nitrification can be maintained using very low-DO concentrations (e.g., below 0.2 mg O2/L), and therefore, it may be possible to reduce energy use and costs in BNR facilities by decreasing aeration. However, the effect of reduced aeration on enhanced biological phosphorus removal (EBPR) is not understood. In this study, we investigated, at the pilot-scale level, the effect of using minimal aeration on the performance of an EBPR process. Over a 16-month operational period, we performed stepwise decreases in aeration, reaching an average DO concentration of 0.33 mg O2/L with stable operation and nearly 90% phosphorus removal. Under these low-DO conditions, nitrification efficiency was maintained, and nearly 70% of the nitrogen was denitrified, without the need for internal recycling of high nitrate aeration basin effluent to the anoxic zone. At the lowest DO conditions used, we estimate a 25% reduction in energy use for aeration compared to conventional BNR operation. Our improved understanding of the efficiency of low-DO BNR contributes to the global goal of reducing energy consumption during wastewater treatment operations.
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Affiliation(s)
- Natalie A Keene
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, USA.
| | | | - Matthew J Scarborough
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, USA.
| | | | - Matt Seib
- Madison Metropolitan Sewerage District, USA.
| | - Jorge Santo Domingo
- Water Supply and Water Resources Division, Environmental Protection Agency, Cincinnati, OH, USA.
| | - Daniel R Noguera
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, USA.
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17
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Tian WD, Ma C, Lin Y, Ran ZL. Effect of Mg/Ca molar ratios on characteristics of anaerobic-anoxic denitrifying dephosphatation. BIORESOURCE TECHNOLOGY 2017; 240:94-97. [PMID: 28202304 DOI: 10.1016/j.biortech.2017.01.063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Revised: 01/26/2017] [Accepted: 01/27/2017] [Indexed: 06/06/2023]
Abstract
In this study, the effect of three Mg/Ca molar ratios (5.0, 3.8 and 1.7) on denitrifying phosphate removal performance, biomass morphology, and Extracellular Polymeric Substances (EPS) were examined. Results showed that when the influent Mg/Ca molar ratio was 3.8, the anaerobic-anoxic EBPR performed complete phosphate removal. The microbial bacterial population was a mixed culture comprised of 81±3% DPAO and 13±2% denitrifying glycogen accumulating organisms (DGAO). A higher influent Mg/Ca molar ratio (5.0) had a distinct impact on phosphate removal, biomass morphology, and EPS. This probably induced the deterioration of the anaerobic-anoxic Enhanced Biological Phosphorus Removal (EBPR). The results of this study may inform the proper operation of an anaerobic-anoxic EBPR, and contribute to its application in the real world.
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Affiliation(s)
- W-D Tian
- School of Environmental Science and Engineering, South University of Science and Technology of China, Shenzhen 518055, PR China.
| | - C Ma
- State Key Laboratory of Separation Membranes and Membrane Processes, School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, PR China; Department of Chemical and Biomolecular Engineering, University of Connecticut, 191 Auditorium Rd. Unit 3222, Storrs, CT 06269-3222, USA
| | - Y Lin
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Z-L Ran
- School of Transportation and Environment, Shenzhen Institute of Information Technology, Shenzhen 518172, PR China
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18
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Zafiriadis I, Kapagiannidis AG, Ntougias S, Aivasidis A. Inhibition of the respiratory chain reactions in denitrifying EBPR biomass under simultaneous presence of acetate and electron acceptor. N Biotechnol 2017; 36:42-50. [DOI: 10.1016/j.nbt.2017.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 12/15/2016] [Accepted: 01/20/2017] [Indexed: 10/20/2022]
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19
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Yuan Y, Liu J, Ma B, Liu Y, Wang B, Peng Y. Improving municipal wastewater nitrogen and phosphorous removal by feeding sludge fermentation products to sequencing batch reactor (SBR). BIORESOURCE TECHNOLOGY 2016; 222:326-334. [PMID: 27728835 DOI: 10.1016/j.biortech.2016.09.103] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 09/22/2016] [Accepted: 09/25/2016] [Indexed: 06/06/2023]
Abstract
This study presents a novel strategy to improve the removal efficiency of nitrogen and phosphorus from municipal wastewater by feeding sequencing batch reactor (SBR) with sludge alkaline fermentation products as carbon sources. The performances of two SBRs treating municipal wastewater (one was fed with sludge fermentation products; F-SBR, and the other without sludge fermentation products; B-SBR) were compared. The removal efficiencies of total nitrogen (TN) and phosphorus (PO43--P) were found to be 82.9% and 96.0% in F-SBR, while the corresponding values in B-SBR were 55.9% (TN) and -6.1% (PO43--P). Illumina MiSeq sequencing indicated that ammonium-oxidizing bacteria (Nitrosomonadaceae and Nitrosomonas) and denitrifying polyphosphate accumulating organisms (Dechloromonas) were enriched in F-SBR, which resulted in NO2--N accumulation and denitrifying phosphorus removal via nitrite (DPRN). Moreover, feeding of sludge fermentation products reduced 862.1mg VSS/d of sludge in the F-SBR system (volume: 10L).
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Affiliation(s)
- Yue Yuan
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Jinjin Liu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Bin Ma
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Ye Liu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Bo Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
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20
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Saad SA, Welles L, Abbas B, Lopez-Vazquez CM, van Loosdrecht MCM, Brdjanovic D. Denitrification of nitrate and nitrite by 'Candidatus Accumulibacter phosphatis' clade IC. WATER RESEARCH 2016; 105:97-109. [PMID: 27603967 DOI: 10.1016/j.watres.2016.08.061] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 08/17/2016] [Accepted: 08/29/2016] [Indexed: 06/06/2023]
Abstract
Phosphate accumulating organisms (PAO) are assumed to use nitrate as external electron acceptor, allowing an efficient integration of simultaneous nitrogen and phosphate removal with minimal organic carbon (COD) requirements. However, contradicting findings appear in literature regarding the denitrification capacities of PAO due to the lack of clade specific highly enriched PAO cultures. Whereas some studies suggest that only PAO clade I may be capable of using nitrate as external electron acceptor for anoxic P-uptake, other studies indicate that PAO clade II may be responsible for anoxic P-removal. In the present study, a highly enriched PAO clade IC culture (>99% according to FISH) was cultivated in an SBR operated under Anaerobic/Oxic conditions and subsequently exposed to Anaerobic/Anoxic/Oxic conditions using nitrate as electron acceptor. Before and after acclimatization to the presence of nitrate, the aerobic and anoxic (nitrate and nitrite) activities of the PAO I culture were assessed through the execution of batch tests using either acetate or propionate as electron donor. In the presence of nitrate, significant P-uptake by PAO I was not observed before or after acclimatization. Using nitrite as electron acceptor, limited nitrite removal rates were observed before acclimatization with lower rates in the acetate fed reactor without P-uptake and slightly higher in the propionate fed reactor with a marginal anoxic P-uptake. Only after acclimatization to nitrate, simultaneous P and nitrite removal was observed. This study suggests that PAO clade IC is not capable of using nitrate as external electron acceptor for anoxic P-removal. The elucidation of the metabolic capacities for individual PAO clades helps in better understanding and optimization of the relation between microbial ecology and process performance in enhanced biological phosphate removal processes.
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Affiliation(s)
- Sondos A Saad
- Department of Civil Engineering, Faculty of Engineering, Ain Shams University, 1 El Sarayat St., Abbassia, 11517 Cairo, Egypt; Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands.
| | - Laurens Welles
- Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands; Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
| | - Ben Abbas
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
| | - Carlos M Lopez-Vazquez
- Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands.
| | - Mark C M van Loosdrecht
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
| | - Damir Brdjanovic
- Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands; Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
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21
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Camejo PY, Owen BR, Martirano J, Ma J, Kapoor V, Santo Domingo J, McMahon KD, Noguera DR. Candidatus Accumulibacter phosphatis clades enriched under cyclic anaerobic and microaerobic conditions simultaneously use different electron acceptors. WATER RESEARCH 2016; 102:125-137. [PMID: 27340814 PMCID: PMC7323474 DOI: 10.1016/j.watres.2016.06.033] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/26/2016] [Accepted: 06/13/2016] [Indexed: 05/05/2023]
Abstract
Lab- and pilot-scale simultaneous nitrification, denitrification and phosphorus removal-sequencing batch reactors were operated under cyclic anaerobic and micro-aerobic conditions. The use of oxygen, nitrite, and nitrate as electron acceptors by Candidatus Accumulibacter phosphatis during the micro-aerobic stage was investigated. A complete clade-level characterization of Accumulibacter in both reactors was performed using newly designed qPCR primers targeting the polyphosphate kinase gene (ppk1). In the lab-scale reactor, limited-oxygen conditions led to an alternated dominance of Clade IID and IC over the other clades. Results from batch tests when Clade IC was dominant (i.e., >92% of Accumulibacter) showed that this clade was capable of using oxygen, nitrite and nitrate as electron acceptors for P uptake. A more heterogeneous distribution of clades was found in the pilot-scale system (Clades IIA, IIB, IIC, IID, IA, and IC), and in this reactor, oxygen, nitrite and nitrate were also used as electron acceptors coupled to phosphorus uptake. However, nitrite was not an efficient electron acceptor in either reactor, and nitrate allowed only partial P removal. The results from the Clade IC dominated reactor indicated that either organisms in this clade can simultaneously use multiple electron acceptors under micro-aerobic conditions, or that the use of multiple electron acceptors by Clade IC is due to significant microdiversity within the Accumulibacter clades defined using the ppk1 gene.
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Affiliation(s)
- Pamela Y Camejo
- Department of Civil and Environmental Engineering, University of Wisconsin - Madison, Madison, WI, USA.
| | - Brian R Owen
- Department of Civil and Environmental Engineering, University of Wisconsin - Madison, Madison, WI, USA.
| | - Joseph Martirano
- Department of Civil and Environmental Engineering, University of Wisconsin - Madison, Madison, WI, USA.
| | - Juan Ma
- School of Environmental & Municipal Engineering, Lanzhou Jiaotong University, China.
| | - Vikram Kapoor
- Environmental Protection Agency, Cincinnati, OH, USA.
| | | | - Katherine D McMahon
- Department of Civil and Environmental Engineering, University of Wisconsin - Madison, Madison, WI, USA; Department of Bacteriology, University of Wisconsin - Madison, Madison, WI, USA.
| | - Daniel R Noguera
- Department of Civil and Environmental Engineering, University of Wisconsin - Madison, Madison, WI, USA.
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22
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Wang X, Wang S, Zhao J, Dai X, Li B, Peng Y. A novel stoichiometries methodology to quantify functional microorganisms in simultaneous (partial) nitrification-endogenous denitrification and phosphorus removal (SNEDPR). WATER RESEARCH 2016; 95:319-329. [PMID: 27016642 DOI: 10.1016/j.watres.2015.12.046] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/22/2015] [Accepted: 12/28/2015] [Indexed: 06/05/2023]
Abstract
Although efficient removal of carbon (C), nitrogen (N) and phosphorous (P) from wastewater with low C/N ratio was achieved in anaerobic/aerobic simultaneous nitrification-endogenous denitrification and phosphorus removal (SNEDPR) systems, the removal pathways and metabolic transformations in this complex system are unclear. This work targeted at developing the stoichiometric models for denitrifying glycogen organisms (DGAOs) via nitrite and nitrate (DGAONi and DGAONa), and demonstrating a novel methodology to quantify diverse functional microorganisms (e.g. ammonia and nitrite oxidizing bacteria, aerobic phosphorus accumulating organisms (APAOs), denitrifying PAOs (DPAOs) and aerobic GAOs (AGAOs)) for the removal of C, N and P. The results showed that the anaerobic intracellular carbon storage (CODintra) was mainly accomplished by GAOs, and PAOs were only responsible for about 40% of CODintra through a stable P release. At the aerobic stage, 84.9% of P was removed by APAOs with 15.1% left by DPAOs, while 64.6% of N was removed by DGAOs (45.8% by DGAONi and 18.8% by DGAONa) with 18.1% by DPAOs and 17.3% by bacterial growth. High proportion of N removal via nitrite (partial nitrification-endogenous denitrification) (71%) saved 7.3% aeration and 38% intracellular carbon demand. However, AGAOs still activated well at the aerobic intercellular carbon consumption, which limited the further improvement of N removal efficiency. By elucidating the nutrient removal pathways among diverse functional microorganisms, the methodology developed in this study could accelerate the nutrient removal in the SNEDPR process.
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Affiliation(s)
- Xiaoxia Wang
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Shuying Wang
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
| | - Ji Zhao
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Xian Dai
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Baikun Li
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China; Department of Civil and Environmental Engineering, University of Connecticut, Storrs, CT 06269, USA
| | - Yongzhen Peng
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
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23
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Tayà C, Guerrero J, Suárez-Ojeda ME, Guisasola A, Baeza JA. Assessment of crude glycerol for Enhanced Biological Phosphorus Removal: Stability and role of long chain fatty acids. CHEMOSPHERE 2015; 141:50-56. [PMID: 26092200 DOI: 10.1016/j.chemosphere.2015.05.067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Revised: 05/04/2015] [Accepted: 05/19/2015] [Indexed: 06/04/2023]
Abstract
Enhanced Biological Phosphorus Removal (EBPR) of urban wastewaters is usually limited by the available carbon source required by Polyphosphate Accumulating Organisms (PAO). External carbon sources as volatile fatty acids (VFA) or other pure organic compounds have been tested at lab scale demonstrating its ability to enhance PAO activity, but the application of this strategy at full-scale WWTPs is not cost-effective. The utilization of industrial by-products with some of these organic compounds provides lower cost, but it has the possible drawback of having inhibitory or toxic compounds to PAO. This study is focused on the utilization of crude glycerol, the industrial by-product generated in the biodiesel production, as a possible carbon source to enhance EBPR in carbon-limited urban wastewaters. Crude glycerol has non-negligible content of other organic compounds as methanol, salts, VFA and long chain fatty acids (LCFA). VFA and methanol have been demonstrated to enhance PAO activity, but there is no previous study about the effect of LCFA on PAO. This work presents the operation of an EBPR SBR system using crude glycerol as sole carbon source, studying also its long-term stability. The effect of LCFA is evaluated at short and long-term operation, demonstrating for the first time EBPR activity with LCFA as sole carbon source and its long-term failure due to the increased hydrophobicity of the sludge.
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Affiliation(s)
- Carlota Tayà
- GENOCOV, Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | - Javier Guerrero
- GENOCOV, Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | - María Eugenia Suárez-Ojeda
- GENOCOV, Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | - Albert Guisasola
- GENOCOV, Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | - Juan Antonio Baeza
- GENOCOV, Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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24
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Wang X, Wang S, Xue T, Li B, Dai X, Peng Y. Treating low carbon/nitrogen (C/N) wastewater in simultaneous nitrification-endogenous denitrification and phosphorous removal (SNDPR) systems by strengthening anaerobic intracellular carbon storage. WATER RESEARCH 2015; 77:191-200. [PMID: 25875928 DOI: 10.1016/j.watres.2015.03.019] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 03/18/2015] [Accepted: 03/19/2015] [Indexed: 06/04/2023]
Abstract
A novel simultaneous nitrification denitrification and phosphorous removal-sequencing batch reactor (SNDPR-SBR) enriched with PAOs (phosphorus accumulating organisms), DPAOs (denitrifying PAOs), and GAOs (glycogen accumulating organisms) at the ratio of 2:1:1 was developed to achieve the simultaneous nutrient and carbon removal treating domestic wastewater with low carbon/nitrogen ratio (≤3.5). The SNDPR system was operated for 120 days at extended anaerobic stage (3 h) and short aerobic stage at low oxygen concentration (2.5 h) with short sludge retention time (SRT) of 10.9 d and hydraulic retention time (HRT) of 14.6 h. The results showed that at the stable operating stage, the average effluent chemical oxygen demand (COD) and PO4(3-)-P concentrations were 47.2 and 0.2 mg L(-1), respectively, the total nitrogen (TN) removal efficiency was 77.7%, and the SND efficiency reached 49.3%. Extended anaerobic stage strengthened the intracellular carbon (mainly poly-β-hydroxybutyrate, PHB) storage, efficiently utilized the organic substances in wastewater, and provided sufficient carbon sources for denitrification and phosphorus uptake without external carbon addition. Short aerobic stage at low oxygen concentration (dissolved oxygen (DO): 1 ± 0.3 mg L(-1)) achieved a concurrence of nitrification, endogenous denitrification, denitrifying and aerobic phosphorus uptake, and saved about 65% energy consumption for aeration. Microbial community analysis demonstrated that P removal was mainly performed by aerobic PAOs while N removal was mainly carried out by denitrifying GAOs (DGAOs), even though DPAOs were also participated in both N and P removal.
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Affiliation(s)
- Xiaoxia Wang
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Shuying Wang
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Tonglai Xue
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Baikun Li
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China; Department of Civil and Environmental Engineering, University of Connecticut, Storrs, CT, 06269, USA
| | - Xian Dai
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Yongzhen Peng
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China.
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Wang Y, Zhou S, Wang H, Ye L, Qin J, Lin X. Comparison of endogenous metabolism during long-term anaerobic starvation of nitrite/nitrate cultivated denitrifying phosphorus removal sludges. WATER RESEARCH 2015; 68:374-386. [PMID: 25462744 DOI: 10.1016/j.watres.2014.09.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 09/26/2014] [Accepted: 09/28/2014] [Indexed: 06/04/2023]
Abstract
Denitrifying phosphorus removal (DPR) by denitrifying phosphorus-accumulating organisms (DPAOs) is a promising approach for reducing energy and carbon usage. However, influent fluctuations or interruptions frequently expose the DPAOs biomass to starvation conditions, reducing biomass activity and amount, and ultimately degrading the performance of DPR. Therefore, a better understanding of the endogenous metabolism and recovery ability of DPAOs is urgently required. In the present study, anaerobic starvation (12 days) and recovery were investigated in nitrite- and nitrate-cultivated DPAOs at 20 ± 1 °C. The cell decay rates in nitrite-DPAOs sludges from the end of the anaerobic and aerobic phase were 0.008 day⁻¹ and 0.007 day⁻¹, respectively, being 64% and 68% lower than those of nitrate-DPAOs sludges. Nitrite-DPAOs sludges also recovered more rapidly than nitrate-DPAOs sludge after 12 days of starvation. The maintenance energy of nitrite-DPAOs sludges from the end of the anaerobic and aerobic phase were approximately 31% and 34% lower, respectively, than those of nitrate-DPAOs sludges. Glycogen and polyphosphate (poly-P) sequentially served as the main maintenance energy sources in both nitrite-and nitrate-DPAOs sludges. However, the transformation pathway of the intracellular polymers during starvation differed between them. Nitrate-DPAOs sludge used extracellular polymeric substances (EPS) (mainly polysaccharides) as an additional maintenance energy source during the first 3 days of starvation. During this phase, EPS appeared to contribute to 19-27% of the ATP production in nitrate-DPAOs, but considerably less to the cell maintenance of nitrite-DPAOs. The high resistance of nitrite-DPAOs to starvation might be attributable to frequent short-term starvation and exposure to toxic substances such as nitrite/free nitrous acids in the parent nitrite-fed reactor. The strong resistance of nitrite-DPAOs sludge to anaerobic starvation may be exploited in P removal by shortcut denitrification processes.
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Affiliation(s)
- Yayi Wang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China.
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26
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Wang Y, Zhou S, Ye L, Wang H, Stephenson T, Jiang X. Nitrite survival and nitrous oxide production of denitrifying phosphorus removal sludges in long-term nitrite/nitrate-fed sequencing batch reactors. WATER RESEARCH 2014; 67:33-45. [PMID: 25261626 DOI: 10.1016/j.watres.2014.08.052] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 08/27/2014] [Accepted: 08/30/2014] [Indexed: 06/03/2023]
Abstract
Nitrite-based phosphorus (P) removal could be useful for innovative biological P removal systems where energy and carbon savings are a priority. However, using nitrite for denitrification may cause nitrous oxide (N2O) accumulation and emissions. A denitrifying nitrite-fed P removal system [Formula: see text] was successfully set up in a sequencing batch reactor (SBR) and was run for 210 days. The maximum pulse addition of nitrite to [Formula: see text] was 11 mg NO2(-)-N/L in the bulk, and a total of 34 mg NO2(-)-N/L of nitrite was added over three additions. Fluorescent in situ hybridization results indicated that the P-accumulating organisms (PAOs) abundance was 75 ± 1.1% in [Formula: see text] , approximately 13.6% higher than that in a parallel P removal SBR using nitrate [Formula: see text] . Type II Accumulibacter (PAOII) (unable to use nitrate as an electron acceptor) was the main PAOs species in [Formula: see text] , contributing 72% to total PAOs. Compared with [Formula: see text] , [Formula: see text] biomass had enhanced nitrite/free nitrous acid (FNA) endurance, as demonstrated by its higher nitrite denitrification and P uptake rates. N2O accumulated temporarily in [Formula: see text] after each pulse of nitrite. Peak N2O concentrations in the bulk for [Formula: see text] were generally 6-11 times higher than that in [Formula: see text] ; these accumulations were rapidly denitrified to nitrogen gases. N2O concentration increased rapidly in nitrate-cultivated biomass when 5 or 10 mg NO2(-)-N/L per pulse was added. Whereas, N2O accumulation did not occur in nitrite-cultivated biomass until up to 30 mg NO2(-)-N/L per pulse was added. Long-term acclimation to nitrite and pulse addition of nitrite in [Formula: see text] reduced the risk of nitrite accumulation, and mitigated N2O accumulation and emissions from denitrifying P removal by nitrite.
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Affiliation(s)
- Yayi Wang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China.
| | - Shuai Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
| | - Liu Ye
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane 4072, Australia
| | - Hong Wang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
| | | | - Xuxin Jiang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
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Jabari P, Munz G, Oleszkiewicz JA. Selection of denitrifying phosphorous accumulating organisms in IFAS systems: comparison of nitrite with nitrate as an electron acceptor. CHEMOSPHERE 2014; 109:20-27. [PMID: 24873702 DOI: 10.1016/j.chemosphere.2014.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 03/02/2014] [Accepted: 03/05/2014] [Indexed: 06/03/2023]
Abstract
Nitrite and nitrate were compared as electron acceptors to select for denitrifying phosphorous accumulating organisms (DPAO) in two integrated fixed film activated sludge (IFAS 1 and IFAS 2) systems operated as sequencing batch reactors. The bench-scale experiment lasted one year and synthetic wastewater was used as feed. During anoxic conditions 20mgNO3(-)-NL(-1) were dosed into IFAS-1 and 20mgNO2(-)-NL(-1) were dosed into IFAS-2. Long term phosphorous and ammonia removal via nitritation were achieved in both systems and both attached and suspended biomass contributed to phosphorous and ammonia removal. DPAO showed no specific adaptation to the electron acceptor as evidenced by short term switch of feeding with nitrate or nitrite. Anoxic phosphorus uptake rate was significantly higher with nitrite than with nitrate. Results showed that DPAO activity with nitrite could be integrated into attached and suspended biomass of IFAS systems in long term operation.
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Affiliation(s)
- Pouria Jabari
- Department of Civil Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada.
| | - Giulio Munz
- Department of Civil Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada; Department of Civil and Environmental Engineering, University of Florence, Via S. Marta 3, 50139 Florence, Italy
| | - Jan A Oleszkiewicz
- Department of Civil Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
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Tayà C, Garlapati VK, Guisasola A, Baeza JA. The selective role of nitrite in the PAO/GAO competition. CHEMOSPHERE 2013; 93:612-618. [PMID: 23845433 DOI: 10.1016/j.chemosphere.2013.06.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 06/04/2013] [Accepted: 06/05/2013] [Indexed: 06/02/2023]
Abstract
Proliferation of Glycogen Accumulating Organisms (GAOs) accounts as one of the major bottlenecks in biological phosphorus removal systems. GAO outcompeting polyphosphate accumulating organisms (PAOs) results in lower P-removal. Thus, finding optimal conditions that favour PAO in front of GAO is a current focus of research. This work shows how nitrite can provide a novel strategy for PAO enrichment. A propionate-fed GAO-enriched biomass (70% Defluviicoccus I, 18% Defluviicoccus II and 10% PAO) was subjected more than 50 d under anaerobic-anoxic conditions with nitrite as electron acceptor. These operational conditions led to a PAO-enriched sludge (85%) where GAO were washed out of the system (<10%), demonstrating the validity of the new approach for PAO enrichment. In addition, the presented suppression of Defluviicocus GAO with nitrite represents an add-on benefit to the nitrite-based systems since the proliferation of non-desirable GAO can be easily ruled out and added to the other benefits (i.e. lower aeration and COD requirements).
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Affiliation(s)
- Carlota Tayà
- Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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Flowers JJ, He S, Malfatti S, del Rio TG, Tringe SG, Hugenholtz P, McMahon KD. Comparative genomics of two 'Candidatus Accumulibacter' clades performing biological phosphorus removal. ISME JOURNAL 2013; 7:2301-14. [PMID: 23887171 DOI: 10.1038/ismej.2013.117] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 05/14/2013] [Accepted: 06/11/2013] [Indexed: 11/09/2022]
Abstract
Members of the genus Candidatus Accumulibacter are important in many wastewater treatment systems performing enhanced biological phosphorus removal (EBPR). The Accumulibacter lineage can be subdivided phylogenetically into multiple clades, and previous work showed that these clades are ecologically distinct. The complete genome of Candidatus Accumulibacter phosphatis strain UW-1, a member of Clade IIA, was previously sequenced. Here, we report a draft genome sequence of Candidatus Accumulibacter spp. strain UW-2, a member of Clade IA, assembled following shotgun metagenomic sequencing of laboratory-scale bioreactor sludge. We estimate the genome to be 80-90% complete. Although the two clades share 16S rRNA sequence identity of >98.0%, we observed a remarkable lack of synteny between the two genomes. We identified 2317 genes shared between the two genomes, with an average nucleotide identity (ANI) of 78.3%, and accounting for 49% of genes in the UW-1 genome. Unlike UW-1, the UW-2 genome seemed to lack genes for nitrogen fixation and carbon fixation. Despite these differences, metabolic genes essential for denitrification and EBPR, including carbon storage polymer and polyphosphate metabolism, were conserved in both genomes. The ANI from genes associated with EBPR was statistically higher than that from genes not associated with EBPR, indicating a high selective pressure in EBPR systems. Further, we identified genomic islands of foreign origins including a near-complete lysogenic phage in the Clade IA genome. Interestingly, Clade IA appeared to be more phage susceptible based on it containing only a single Clustered Regularly Interspaced Short Palindromic Repeats locus as compared with the two found in Clade IIA. Overall, the comparative analysis provided a genetic basis to understand physiological differences and ecological niches of Accumulibacter populations, and highlights the importance of diversity in maintaining system functional resilience.
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Affiliation(s)
- Jason J Flowers
- Departments of Civil and Environmental Engineering, and Bacteriology, University of Wisconsin at Madison, Madison, WI, USA
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31
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Zhang Q, He J, Wang H, Ma F, Yang K, Wang J. Microbial community changes during the start-up of an anaerobic/aerobic/anoxic-type sequencing batch reactor. ENVIRONMENTAL TECHNOLOGY 2013; 34:1211-1217. [PMID: 24191454 DOI: 10.1080/09593330.2012.743595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
An anaerobic/aerobic/anoxic-type sequencing batch reactor was started up during a summer rainy season to obtain enhanced biological phosphorus removal (EBPR), and its sludge microbial community was also monitored in the hope of observing the microbial community evolution of polyphosphate-accumulating organisms (PAOs). During the start-up process, a total of 17 bands of highest species richness were detected in the sludge microbial community, including Alpha-, Beta-, and Gamma- Proteobacteria, as well as Actinobacteria and Planctomycetes. Major microbial community structural change was observed in Rhodocyclus-related and Acinetobacter-related PAOs, glycogen-accumulating organisms (GAOs), and Actinobacteria. In contrast to the current belief that enrichment of PAOs is essential for the establishment of EBPR, PAOs were not favourably enriched in this study. Instead, Actinobacteria and GAOs overwhelmingly flourished. The overall conclusion of this study challenges the conventional view that EBPR cannot live without traditional PAOs. However, it suggests an non-negligible role of denitrifying phosphorus-accumulating bacteria in EBPR systems, as well as other uncultured bacteria.
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Affiliation(s)
- Qian Zhang
- School of Civil Engineering & Architecture, Wuhan University of Technology, Wuhan, PR China
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32
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Characterization of the denitrification-associated phosphorus uptake properties of "Candidatus Accumulibacter phosphatis" clades in sludge subjected to enhanced biological phosphorus removal. Appl Environ Microbiol 2013; 79:1969-79. [PMID: 23335771 DOI: 10.1128/aem.03464-12] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To characterize the denitrifying phosphorus (P) uptake properties of "Candidatus Accumulibacter phosphatis," a sequencing batch reactor (SBR) was operated with acetate. The SBR operation was gradually acclimated from anaerobic-oxic (AO) to anaerobic-anoxic-oxic (A2O) conditions by stepwise increases of nitrate concentration and the anoxic time. The communities of "Ca. Accumulibacter" and associated bacteria at the initial (AO) and final (A2O) stages were compared using 16S rRNA and polyphosphate kinase genes and using fluorescence in situ hybridization (FISH). The acclimation process led to a clear shift in the relative abundances of recognized "Ca. Accumulibacter" subpopulations from clades IIA > IA > IIF to clades IIC > IA > IIF, as well as to increases in the abundance of other associated bacteria (Dechloromonas [from 1.2% to 19.2%] and "Candidatus Competibacter phosphatis" [from 16.4% to 20.0%]), while the overall "Ca. Accumulibacter" abundance decreased (from 55.1% to 29.2%). A series of batch experiments combined with FISH/microautoradiography (MAR) analyses was performed to characterize the denitrifying P uptake properties of the "Ca. Accumulibacter" clades. In FISH/MAR experiments using slightly diluted sludge (∼0.5 g/liter), all "Ca. Accumulibacter" clades successfully took up phosphorus in the presence of nitrate. However, the "Ca. Accumulibacter" clades showed no P uptake in the presence of nitrate when the sludge was highly diluted (∼0.005 g/liter); under these conditions, reduction of nitrate to nitrite did not occur, whereas P uptake by "Ca. Accumulibacter" clades occurred when nitrite was added. These results suggest that the "Ca. Accumulibacter" cells lack nitrate reduction capabilities and that P uptake by "Ca. Accumulibacter" is dependent upon nitrite generated by associated nitrate-reducing bacteria such as Dechloromonas and "Ca. Competibacter."
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33
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Tayà C, Guerrero J, Vanneste G, Guisasola A, Baeza JA. Methanol-driven enhanced biological phosphorus removal with a syntrophic consortium. Biotechnol Bioeng 2012; 110:391-400. [DOI: 10.1002/bit.24625] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 07/16/2012] [Accepted: 07/26/2012] [Indexed: 11/06/2022]
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Bassin JP, Kleerebezem R, Dezotti M, van Loosdrecht MCM. Simultaneous nitrogen and phosphate removal in aerobic granular sludge reactors operated at different temperatures. WATER RESEARCH 2012; 46:3805-3816. [PMID: 22591819 DOI: 10.1016/j.watres.2012.04.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Revised: 04/05/2012] [Accepted: 04/07/2012] [Indexed: 05/31/2023]
Abstract
The main biological conversions taking place in two lab-scale aerobic granular sludge sequencing batch reactors were evaluated. Reactors were operated at different temperatures (20 and 30 °C) and accomplished simultaneous COD, nitrogen and phosphate removal. Nitrogen and phosphate conversions were linked to the microbial community structure as assessed by fluorescent in situ hybridization (FISH) analysis. Anoxic tests were performed to evaluate the contribution of anoxic phosphate uptake to the overall phosphate removal and to clarify the denitrification pathway. Complete nitrification/denitrification and phosphate removal were achieved in both systems. A considerable fraction of the phosphate removal was coupled to denitrification (denitrifying dephosphatation). From the results obtained in anoxic batch experiments dosing either nitrite or nitrate, denitrification was proposed to proceed mainly via the nitrate pathway. Denitrifying glycogen-accumulating organisms (DGAOs) were observed to be the main organisms responsible for the reduction of nitrate to nitrite. A significant fraction of the nitrite was further reduced to nitrogen gas while being used as electron acceptor by denitrifying polyphosphate-accumulating organisms (PAO clade II) for anoxic phosphate uptake.
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Affiliation(s)
- J P Bassin
- Delft University of Technology, Department of Biotechnology, Delft, The Netherlands
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35
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Guerrero J, Tayà C, Guisasola A, Baeza JA. Glycerol as a sole carbon source for enhanced biological phosphorus removal. WATER RESEARCH 2012; 46:2983-2991. [PMID: 22459328 DOI: 10.1016/j.watres.2012.02.043] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 02/24/2012] [Accepted: 02/26/2012] [Indexed: 05/31/2023]
Abstract
Wastewaters with low organic matter content are one of the major causes of EBPR failures in full-scale WWTP. This carbon source deficit can be solved by external carbon addition and glycerol is a perfect candidate since it is nowadays obtained in excess from biodiesel production. This work shows for the first time that glycerol-driven EBPR with a single-sludge SBR configuration is feasible (i.e. anaerobic glycerol degradation linked to P release and aerobic P uptake). Two different strategies were studied: direct replacement of the usual carbon source for glycerol and a two-step consortium development with glycerol anaerobic degraders and PAO. The first strategy provided the best results. The implementation of glycerol as external carbon source in full-scale WWTP would require a suitable anaerobic hydraulic retention time. An example using dairy wastewater with a low COD/P ratio confirms the feasibility of using glycerol as an external carbon source to increase P removal activity. The approach used in this work opens a new range of possibilities and, similarly, other fermentable substrates can be used as electron donors for EBPR.
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Affiliation(s)
- Javier Guerrero
- Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain.
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Guerrero J, Guisasola A, Baeza JA. The nature of the carbon source rules the competition between PAO and denitrifiers in systems for simultaneous biological nitrogen and phosphorus removal. WATER RESEARCH 2011; 45:4793-4802. [PMID: 21774957 DOI: 10.1016/j.watres.2011.06.019] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 06/15/2011] [Accepted: 06/17/2011] [Indexed: 05/31/2023]
Abstract
The presence of nitrate in the theoretical anaerobic reactor of a municipal WWTP aiming at simultaneous C, N and P removal usually leads to Enhanced Biological Phosphorus Removal (EBPR) failure due to the competition between PAO and denitrifiers for organic substrate. This problem was studied in a continuous anaerobic-anoxic-aerobic (A2/O) pilot plant (146 L) operating with good removal performance and a PAO-enriched sludge (72%). Nitrate presence in the initially anaerobic reactor was studied by switching the operation of the plant to an anoxic-aerobic configuration. When the influent COD composition was a mixture of different carbon sources (acetic acid, propionic acid and sucrose) the system was surprisingly able to maintain EBPR, even with internal recycle ratios up to ten times the influent flow rate and COD limiting conditions. However, the utilisation of sucrose as sole carbon source resulted in a fast EBPR failure. Batch tests with different nitrate concentrations (0-40 mg L(-1)) were performed in order to gain insight into the competition for the carbon source in terms of P-release or denitrification rates and P-release/C-uptake ratio. Surprisingly, no inhibitory or detrimental effect on EBPR performance due to nitrate was observed. A model based on ASM2d but considering two step nitrification and denitrification was developed and experimentally validated. Simulation studies showed that anaerobic VFA availability is critical to maintain EBPR activity.
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Affiliation(s)
- Javier Guerrero
- Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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37
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Tayà C, Guisasola A, Baeza JA. Assessment of a bioaugmentation strategy with polyphosphate accumulating organisms in a nitrification/denitrification sequencing batch reactor. BIORESOURCE TECHNOLOGY 2011; 102:7678-7684. [PMID: 21683580 DOI: 10.1016/j.biortech.2011.05.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 05/16/2011] [Accepted: 05/18/2011] [Indexed: 05/30/2023]
Abstract
Different alternative configurations and strategies for the simultaneous biological removal of organic matter and nutrients (N and P) in wastewater have been proposed in the literature. This work demonstrates a new successful strategy to bring in enhanced biological phosphorus removal (EBPR) to a conventional nitrification/denitrification system by means of bioaugmentation with an enriched culture of phosphorus accumulating organisms (PAO). This strategy was tested in a sequencing batch reactor (SBR), where an 8h configuration with 3h anoxic, 4.5h aerobic and 25 min of settling confirmed that nitrification, denitrification and PAO activity could be maintained for a minimum of 60 days of operation after the bioaugmentation step. The successful bioaugmentation strategy opens new possibilities for retrofitting full-scale WWTP originally designed for only nitrification/denitrification. These systems could remove P simultaneously to COD and N if they were bioaugmented with waste purge of an anaerobic/aerobic SBR operated in parallel treating part of the influent wastewater.
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Affiliation(s)
- Carlota Tayà
- Departament d'Enginyeria Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
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38
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Zeng W, Yang Y, Li L, Wang X, Peng Y. Effect of nitrite from nitritation on biological phosphorus removal in a sequencing batch reactor treating domestic wastewater. BIORESOURCE TECHNOLOGY 2011; 102:6657-6664. [PMID: 21511460 DOI: 10.1016/j.biortech.2011.03.091] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 02/28/2011] [Accepted: 03/28/2011] [Indexed: 05/30/2023]
Abstract
Although nitrite effect on enhanced biological phosphorus removal (EBPR) has been previously studied, very limited research has been undertaken about the effect of nitrite accumulation caused by nitritation on EBPR. This paper focused on nitrite effect from nitritation on EBPR in a sequencing batch reactor treating domestic wastewater. Results showed that nitrite of below 10mg/L did not inhibit P-uptake and release; whereas EBPR deterioration was observed when nitrite accumulation reached 20mg/L. Due to P-uptake prior to nitritation, nitrite of 20mg/L has no effect on aerobic P-uptake. The main reason leading to EBPR deterioration was the competition of carbon source. Batch tests were conducted to investigate nitrite effect on anaerobic P-release. Under sufficient carbon source, nitrite of 30 mg/L had no impact on poly-β-hydroxyalkanoate (PHA) storage; contrarily, under insufficient carbon source, denitrifiers competing for carbon source with phosphorus accumulating organisms resulted in decrease of PHA synthesis and P-release.
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Affiliation(s)
- Wei Zeng
- Key Laboratory of Beijing for Water Environment Recovery, Department of Environmental Engineering, Beijing University of Technology, Beijing 100124, China.
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39
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Vargas M, Guisasola A, Artigues A, Casas C, Baeza J. Comparison of a nitrite-based anaerobic–anoxic EBPR system with propionate or acetate as electron donors. Process Biochem 2011. [DOI: 10.1016/j.procbio.2010.11.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
‘Candidatus Accumulibacter’ is a biotechnologically important bacterial group that can accumulate large amounts of intracellular polyphosphate, contributing to biological phosphorus removal in wastewater treatment. Since its first molecular identification more than a decade ago, this bacterial group has drawn significant research attention due to its high abundance in many biological phosphorus removal systems. In the past 6 years, our understanding of Accumulibacter microbiology and ecophysiology has advanced rapidly, largely owing to genomic information obtained through shotgun metagenomic sequencing efforts. In this review, we focus on the metabolism, physiology, fine‐scale population structure and ecological distribution of Accumulibacter, aiming to integrate the information learned so far and to present a more complete picture of the microbiology of this important bacterial group.
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Affiliation(s)
- Shaomei He
- Department of Civil and Environmental Engineering Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
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41
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Oehmen A, Carvalho G, Lopez-Vazquez CM, van Loosdrecht MCM, Reis MAM. Incorporating microbial ecology into the metabolic modelling of polyphosphate accumulating organisms and glycogen accumulating organisms. WATER RESEARCH 2010; 44:4992-5004. [PMID: 20650504 DOI: 10.1016/j.watres.2010.06.071] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 06/25/2010] [Accepted: 06/30/2010] [Indexed: 05/29/2023]
Abstract
In the enhanced biological phosphorus removal (EBPR) process, the competition between polyphosphate accumulating organisms (PAO) and glycogen accumulating organisms (GAO) has been studied intensively in recent years by both microbiologists and engineers, due to its important effects on phosphorus removal performance and efficiency. This study addresses the impact of microbial ecology on assessing the PAO-GAO competition through metabolic modelling, focussing on reviewing recent developments, discussion of how the results from molecular studies can impact the way we model the process, and offering perspectives for future research opportunities based on unanswered questions concerning PAO and GAO metabolism. Indeed, numerous findings that are seemingly contradictory could in fact be explained by the metabolic behaviour of different sub-groups of PAOs and/or GAOs exposed to different environmental and operational conditions. Some examples include the glycolysis pathway (i.e. Embden-Meyerhof-Parnas (EMP) vs. Entner-Doudoroff (ED)), denitrification capacity, anaerobic tricarboxylic acid (TCA) cycle activity and PAOs' ability to adjust their metabolism to e.g. a GAO-like metabolism. Metabolic modelling may further yield far-reaching influences on practical applications as well, and serves as a bridge between molecular/biochemical research studies and the optimisation of wastewater treatment plant operation.
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Affiliation(s)
- A Oehmen
- REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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Flowers JJ, He S, Yilmaz S, Noguera DR, McMahon KD. Denitrification capabilities of two biological phosphorus removal sludges dominated by different "Candidatus Accumulibacter" clades. ENVIRONMENTAL MICROBIOLOGY REPORTS 2009; 1:583-588. [PMID: 20808723 PMCID: PMC2929836 DOI: 10.1111/j.1758-2229.2009.00090.x] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The capability of "Candidatus Accumulibacter" to use nitrate as an electron acceptor for phosphorus uptake was investigated using two activated sludge communities. The two communities were enriched in Accumulibacter clade IA and clade IIA, respectively. By performing a series of batch experiments, we found that clade IA was able to couple nitrate reduction with phosphorus uptake, but clade IIA could not. These results agree with a previously proposed hypothesis that different populations of Accumulibacter have different nitrate reduction capabilities, and they will help to understand the ecological roles that these two clades provide.
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Affiliation(s)
- Jason J. Flowers
- Department of Civil and Environmental Engineering, University of Wisconsin at Madison, Madison, WI, 53706, USA
| | - Shaomei He
- Department of Civil and Environmental Engineering, University of Wisconsin at Madison, Madison, WI, 53706, USA
| | - Safak Yilmaz
- Department of Civil and Environmental Engineering, University of Wisconsin at Madison, Madison, WI, 53706, USA
| | - Daniel R. Noguera
- Department of Civil and Environmental Engineering, University of Wisconsin at Madison, Madison, WI, 53706, USA
| | - Katherine D. McMahon
- Department of Civil and Environmental Engineering, University of Wisconsin at Madison, Madison, WI, 53706, USA
- Department of Bacteriology, University of Wisconsin at Madison, Madison, WI, 53706, USA
- corresponding author: Address: 5525 Microbial Science Building, 1550 Linden Dr., Madison, WI 53925, Tel: (608) 263-3137, Fax: (608) 262-5199,
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